There has a known compatible issue on using Intel INT13 BIOS. ARC-1883i INT13 boot device will just disappear because unknown reason, also not exist in the BIOS BDA 40:75h. There is no issue on UEFI mode. You can configure both ARC-1883i RAID controller /System Configuration/BIOS Selection and motherboard bios setting as an UEFI BIOS mode. Areca BIOS code version 1.24 date 2016-03-18 has resolved the issue and allows S2600CW to use ARC-1883i in legacy BIOS mode, not just in UEFI.